Overload switch



March 27, 1934. w. LEYHAUSEN OVERLOAD SWITCH Filed Feb. 16, 1931 zzf,

NSUL 4770A/ Patented Mar. 27, 1934 UNITED STATES OVERLOAD SWITCH WilhelmLeyhausen,

Nuremberg, Germany Application February 16, 1931, Serial No. 516,190 InGermany February 28, 1930 6 Claims.

Applications have been led in Germany Feb. 28, 1930, and Oct. 16, 1930.

This invention relates to an overload switch with a pair of magnets, thepoles of which control the release armature, and serve also to establisha magnetic eld for extinguishing the cutout arc. The invention has forits object to pro duce a more effective magnetic spar. extinguishingthan is the case in the known switches of the type mentioned. In theseknown switches, the magnet coils extend around the longitudinal sides ofthe magnet arms so that the axes of the coils are parallel to the arms.According to the invention, the axes of the magnet coils are arranged atright angles to the arms of the magnet. Thus, it becomes possible toplace the break contact between the ends of the two coils, whereby aconsiderably stronger blow-out effect is obtained than heretofore.

It may be suiiicient to arrange only one of the two magnet coils in themanner described, the other coil being placed parallel to the magnet armas heretofore. For the second coil, a magnetizable body may besubstituted which is positioned opposite the iron core of the coil.

The invention relates further to the particular construction of theswitch.

Two embodiments of the invention are illustrated by way of example inthe accompanying drawing in which- Figures 1 to 4 show an overloadswitch in the form of a plug switch with two electromagnets, andparticularly Figure 1 is a vertical section of this form in the plane ofthe coil axes;

Figure 2 is a cross section thereof;

Figure 3 is a bottom plan View thereof with the switching mechanismomitted;

Figure 4 is a ver-tical section at right angles to that shown in Figure1;

Figures 5 to 7 show a switch in which a magnetizable body is arrangedopposite a magnet coil, and particularly Figure 5 is a vertical centralsection of the second form;

Figure 6 is a vertical section at right angles to Figure 5; and

Figure 7 is a cross section transversely of Fig'- ure 5 on the axes ofthe magnet core.

In the casing 1 (Figures 1 to 4) magnet coils 2 and 3 with their ironcores 4 and 5 are arranged at right angles to the axis of the casing. Aspark gap 8 is formed between these coils by the partitions 6 and 7. Inthis spark gap, that is between the ends of the magnet coils 2 and 3,contacts 9 and 10 are arranged. The iron cores are connected by ironarms 12 and 13 with pole pieces 14 and 15 which act on an armature 16.The armature 16 is pivoted at 39. The contact 10 is carried by the upperend of an arm 40 which is iixed to the arm 4l of a lever pivotedintermediate its ends at 11 and having its remaining arm 42 extendingfrom the pivot in a direction opposite to the arm 41. A spring 45 hasone end secured to the arm 41 and its other end se- J'cured to a lug 44and this spring normally urges the lever arms 41 and 42 to rotate in aclockwise direction. However, the armature 16 carries a stirrup 46 andlimits movement of the lever in this direction. Upon the circuit beingoverloaded, the armature is liited at its free end and, by means of thestirrup, starts movement of the lever arms in a clockwise direction (seeFig. 4) and this causes the axis of the spring to move downwardly acrossthe pivot axis 11 so that the spring urges the arm 41 downwardly and thelever is snapped into full clockwise position, thus quickly movingContact 10 to the dotted line position. The magnets act to blow out theelectric arc between the contacts 9 and 10. As the breaking occurs in anextremely dense magnetic iield and the. magnetic lines of forceintersect the arcat right angles, the blowing effect oi the switch isparticularly strong. In order to reset the switch, a stem 48 projectsfrom the end closure ofthe device and carries a spring-pressed pushbutton 4'7 which, when the switch is open and the button is pressedupward, will engage the arm 41 and cause it to move in an anti-clockwisedirection until the contact 10 closes on the Contact 9.

Figures 2 and 3 show the advantageous utilization of space of theswitch. The coils and iron parts are adapted to the curvature of theswitch casing. The spark gap is larger than in other switches. In orderto obtain the largest possible blowing field, the coils and iron coresare substantially rectangular and their longitudinal sides lie in thelongitudinal direction of the switch. A plurality of contacts may alsobe provided and the switching mechanism constructed in any desiredmanner. The end faces of the iron cores may be enlarged in known mannerby flanges.

The construction illustrated with the cores 4 and 5 situated closetogether and with the coils surrounding the iron parts 12, 13, 14, 15and 16 presents the further advantage that the device acts as a chokingcoil in the case of strong short circuits and limits the intensity ofthe short circuit current.

In the switch shown in Figures 5 to '7, the lower part 22 of the switchcasing 21, 22 is covered by an insulating plate 38 and subdivided intothree compartments of different size by two Vertical insulating walls 24and 25 which engage in the outer wall. In the middle, narrowcompartment, limited by the walls 24 and 25, contacts 26 and 27 arearranged, the Contact 26 being stationary and the contact 27 movable. Inthe larger of the lateral compartments, a magnet coil 28 with its ironcore 29 is arranged transversely to the fcc axis of the switch and onthe outer side an armature 30 is positioned opposite the iron core. Theother lateral compartment contains a magnetizable body 31 which isconnected to a plate 23 also composed of magnetizable material.

The release device is arranged above the plate 23. It consistssubstantially of a cylinder 32, mounted in two bearings. A spring (notshown) tends to rotate this cylinder in a certain direction. In one endof the cylinder 32 a blade spring 33 is clamped and carries the movablecontact 27. The other end of the cylinder is provided on its end facewith a tooth 34 which, in the normal position of the switch isoverlapped by a hook 35 mounted on the upper end of the two armedarmature 30 mounted in the plate 23. A spring 36, pressing against thehook arm, tends to hold the armature in this position. When the cylinder32 is in the position illustrated, which is caused by the hook 35holding it against the action of the spring (not shown) the contacts 27and 26 are in closed position. A hand lever 37 is mounted on the middleportion of the cylinder 32,

If excess current occurs, the armature plate 30 is attracted by the ironcore 29. The hook, sliding off the tooth 34, liberates the cylinder 32which rotates under the action of the spring (not shown) so that themovable contact 27 and the handle 37 jump into the position shown indotted lines.

The releasing device and the contacts may be of any desiredconstruction. The breaking may be effected at several points, and themovement of the contacts may be carried out parallel to the axis of theswitch instead of transversely thereto.

I claim:

1. The combination with a casing having one end shaped like a screw plugand through which the magnets are energized, of a pair of spacedelectro-magnets having their magnetic axes alined transversely of thecasing and having the remote ends of their cores magnetically connected,a fixed contact supported by the casing and extending between saidmagnets at one side of the magnetic axis thereof, a movable contactsupported to move into and out of engagement with the fixed contactacross the magnetic axis of the said magnets, said movable contactnormally engaging the fixed Contact, an overload device carried by thecasing and arranged to effeet movement of the movable contact away fromthe fixed contact, and insulating walls between said magnets andcontacts.

2. The combination with a casing having one end shaped like a screw plugand through which the magnets are energized, of a pair of spacedelectro-magnets having their magnetic axes alined transversely of thecasing and having the remote ends of their cores magnetically connected,a xed contact supported by the casing and extending between the saidmagnets at one side of the magnetic axis thereof, a movable contactsupported to move into and out of engagement with said xed contactacross the magnetic axis of said magnets, said movable contact normallyengaging the xed contact, an overload device carried by the casing andarranged to effect movement of the movable contact away from the iixedcontact and including an actuating armature controlled by the eld ofsaid magnets.

3. The combination with a casing having one end shaped like a screw plugand through which the magnets are energized, of a pair of spacedelectro-magnets having their magnetic axes alined transversely oi thecasing and having the remote ends of their cores magnetically connected,a fixed contact supported by the casing and extending between the saidmagnets at one side of the magnetic axis thereof, a movable contactsupported to move into and out of engagement with said fixed contactacross the magnetic axis of the said magnets, said movable contactnormally engaging the xed contact, an overload device carried by thecasing and arranged to effect movement of the movable contact away fromthe ixed contact including an actuating armature controlled by the fieldof said magnets, and insulating walls between said magnets and contacts.

Il. The combination with a casing having one end shaped like a screwplug to t an electric socket and through which the magnets areenergized, of a pair of spaced electro-magnets having their magneticaxis alined transversely of the casing, and having the remote ends oftheir cores magnetically connected, a fixed contact supported by thecasing and extending between said magnets at one side of the magneticaxis thereof, a movable contact supported to move into and out ofengagement with said fixed contact across the magnetic axis of saidmagnets, said movable contact normally engaging the fixed contact, and

an overload device carried by the casing and arranged to effect movementof the movable contact away from the fixed contact.

5. The combination with a casing, of a pair of spaced electro-magnetshaving their magnetic axes alined transversely of the casing, a fixedcontact supported by the casing and extending between said magnets atone side of the movable axis thereof, a movable contact supported tomove into and out of engagement with said iixed contact across themagnetic axis ci said magnets, said movable contact normally engagingthe fixed Contact, a lever pivoted intermediate its ends and having themovable contact fixed to one arm, an armature pivoted at one end andmovable under excessive magnetization of said magnets, a stirrup carriedby the armature and engaging the remaining arm of said lever, saidarmature and stirrup being arranged to move the lever in a direction toseparate the contacts, and a snap spring arranged to snap the lever tothe extremity of its movement in each direction.

6. The combination with a casing, of a pair of spaced electro-magnetshaving their magnetic axes alined transversely of the casing, a fixedcontact supported by the casing and extending between said magnets atone side of the movable axis thereof, a movable contact supported tomove into and out of engagement with said fixed contact across themagnetic axis of said magnets, said movable contact normally engagingthe fixed contact, a lever pivoted intermediate its ends and having themovable contact iixed to one arm, an armature pivoted at one end andmovable under excessive magnetization of said magnets, a stirrup carriedby the armature and engaging the remaining arm of said lever, saidarmature and stirrup being arranged to move the lever in a direction toseparate the contacts, a snap spring arranged to snap the lever to theextremity of its movement in each direction, and insulating wallsbetween said magnets and contacts.

WILHELM LEYHAUSEN.

